全文获取类型
收费全文 | 2321篇 |
免费 | 42篇 |
国内免费 | 16篇 |
专业分类
系统科学 | 38篇 |
丛书文集 | 4篇 |
教育与普及 | 2篇 |
理论与方法论 | 4篇 |
现状及发展 | 1088篇 |
研究方法 | 155篇 |
综合类 | 1078篇 |
自然研究 | 10篇 |
出版年
2018年 | 22篇 |
2017年 | 23篇 |
2016年 | 37篇 |
2015年 | 18篇 |
2014年 | 28篇 |
2013年 | 54篇 |
2012年 | 111篇 |
2011年 | 114篇 |
2010年 | 80篇 |
2009年 | 36篇 |
2008年 | 86篇 |
2007年 | 85篇 |
2006年 | 95篇 |
2005年 | 102篇 |
2004年 | 66篇 |
2003年 | 70篇 |
2002年 | 65篇 |
2001年 | 46篇 |
2000年 | 62篇 |
1999年 | 34篇 |
1994年 | 18篇 |
1992年 | 31篇 |
1991年 | 30篇 |
1990年 | 22篇 |
1989年 | 32篇 |
1988年 | 29篇 |
1987年 | 18篇 |
1986年 | 18篇 |
1985年 | 29篇 |
1984年 | 26篇 |
1983年 | 23篇 |
1982年 | 21篇 |
1981年 | 18篇 |
1980年 | 17篇 |
1979年 | 48篇 |
1978年 | 26篇 |
1977年 | 43篇 |
1976年 | 27篇 |
1975年 | 27篇 |
1974年 | 46篇 |
1973年 | 39篇 |
1972年 | 53篇 |
1971年 | 37篇 |
1970年 | 44篇 |
1969年 | 42篇 |
1968年 | 50篇 |
1967年 | 35篇 |
1966年 | 36篇 |
1965年 | 22篇 |
1964年 | 25篇 |
排序方式: 共有2379条查询结果,搜索用时 109 毫秒
141.
An agrin minigene rescues dystrophic symptoms in a mouse model for congenital muscular dystrophy 总被引:21,自引:0,他引:21
Moll J Barzaghi P Lin S Bezakova G Lochmüller H Engvall E Müller U Ruegg MA 《Nature》2001,413(6853):302-307
Congenital muscular dystrophy is a heterogeneous and severe, progressive muscle-wasting disease that frequently leads to death in early childhood. Most cases of congenital muscular dystrophy are caused by mutations in LAMA2, the gene encoding the alpha2 chain of the main laminin isoforms expressed by muscle fibres. Muscle fibre deterioration in this disease is thought to be caused by the failure to form the primary laminin scaffold, which is necessary for basement membrane structure, and the missing interaction between muscle basement membrane and the dystrophin-glycoprotein complex (DGC) or the integrins. With the aim to restore muscle function in a mouse model for this disease, we have designed a minigene of agrin, a protein known for its role in the formation of the neuromuscular junction. Here we show that this mini-agrin-which binds to basement membrane and to alpha-dystroglycan, a member of the DGC-amends muscle pathology by a mechanism that includes agrin-mediated stabilization of alpha-dystroglycan and the laminin alpha5 chain. Our data provides in vivo evidence that a non-homologous protein in combination with rational protein design can be used to devise therapeutic tools that may restore muscle function in human muscular dystrophies. 相似文献
142.
143.
144.
Zaugg CE Spaniol M Kaufmann P Bellahcene M Barbosa V Tolnay M Buser PT Krähenbühl S 《Cellular and molecular life sciences : CMLS》2003,60(4):767-775
Carnitine is essential for mitochondrial metabolism of long-chain fatty acids and thus for myocardial energy production. Accordingly, carnitine deficiency can be associated with cardiomyopathy. To better understand this disease, we determined myocardial function and energy metabolism in a rat model of carnitine deficiency. Carnitine deficiency was induced by a 3- or 6-week diet containing N-trimethyl-hydrazine-3-propionate, reducing cardiac and plasma carnitine by 70-85%. Myocardial function was investigated in isolated isovolumic heart preparations. Carnitine-deficient hearts showed left ventricular systolic dysfunction, reduced contractile reserve, and a blunted frequency-force relationship independently of the substrate used (glucose or palmitate). After glycogen depletion, palmitate could not sustain myocardial function. Histology and activities of carnitine palmitoyl transferase, citrate synthase, and cytochrome c oxidase were unaltered. Thus, as little as 3-6 weeks of systemic carnitine deficiency can lead to abnormalities in myocardial function. These abnormalities are masked by endogenous glycogen and are not accompanied by structural alterations of the myocardium or by altered activities of important mitochondrial enzymes. 相似文献
145.
146.
147.
Human mitochondrial tRNAs in health and disease 总被引:6,自引:0,他引:6
Florentz C Sohm B Tryoen-Tóth P Pütz J Sissler M 《Cellular and molecular life sciences : CMLS》2003,60(7):1356-1375
The human mitochondrial genome encodes 13 proteins, all subunits of the respiratory chain
complexes and thus involved in energy metabolism. These genes are translated by 22 transfer RNAs
(tRNAs), also encoded by the mitochondrial genome, which form the minimal set required for reading
all codons. Human mitochondrial tRNAs gained interest with the rapid discovery of correlations
between point mutations in their genes and various neuromuscular and neurodegenerative disorders.
In this review, emerging fundamental knowledge on the structure/function relationships of these
particular tRNAs and an overview of the large variety of mechanisms within translation, affected by
mutations, are summarized. Also, initial results on wide-ranging molecular consequences of mutations
outside the frame of mitochondrial translation are highlighted. While knowledge of mitochondrial
tRNAs in both health and disease increases, deciphering the intricate network of events leading
different genotypes to the variety of phenotypes requires further investigation using adapted
model systems.Received 3 December 2002; received after revision 14 January 2003; accepted 27 January 2003 相似文献
148.
Kühlbrandt W 《Nature》2003,426(6965):399-400
149.
150.
A broad understanding of the relationship between gene activation, pattern formation and morphogenesis will require adequate tools for three-dimensional and, perhaps four-dimensional, representation and analysis of molecular developmental processes. We present a novel, computer-based method for the 3D visualization of embryonic gene expression and morphological structures from serial sections. The information from these automatically aligned 3D reconstructions exceeds that from single-section and whole-mount visualizations of in situ hybridizations. In addition, these 3D models of gene-expression patterns can become a central component of a future developmental database designed for the collection and presentation of digitized, morphological and gene-expression data. This work is accompanied by a web site (http://www.univie.ac.at/GeneEMAC). 相似文献